Dr. Ickxs

Hi guys.

I have got a problem with my mk3 cabby with S2 running gear.
It's a hearts and diamonds ECU and fuel module with green sticker. Manifold has knock sensor.
Engine has been fully rebuild, an after 500miles of running in (keeping it below 3500rpm), I wanted to go higher in the RPM's.
I notice that the car holds back when getting at 3300rpm....flooring it will get it beyond 3500RPm, and the car starts pulling again. But not like an RS Turbo should do.
Also with a cold start (10-15 degree C), it runs on 2/3 cilinders. After a 5-10 seconds it runs on all 4. Hot start is sometimes perfectly on all 4 and some times, i have to give it some throttle for it to start at all.
I also noticed that my (original) actuator is a bit tired. With half a hole preload, it only allows .3bar (4.5 psi) boost. Took the actuator off the car, and tested it. It opens indeed around 4.5psi.

I checked all hoses ( all are brand new, boost, vacuum, hose to MAP sensor etc) for leaks. I checked the charge air temp sensor and coolant temp sensor with Ohm meter, and all were within spec. I used contactcleaner on the connectors, and checked for damaged wiring. ( I haven't measured on ECU plug with Ohm meter yet) disconnected the plug on 5th injector. Haven't checked the 5th injector for leaks yet....
Mixture has been set up, using the "press paddle 1mm during hot idle and see if rpm increase or decrease" method.
Ignition timing is set up. Complete distributer is an original Bosch brand new item. Coil is used. New leads. New motorcraft sparkplugs (150 miles)

Fuel flow has been checked, and is within spec. Pressure still needs to be checked, because I don't own a fuel pressure gauge.

I can't see any distinctive colour smoke from exhaust. All looks ok.

I am going to set up the mixture (CO) properly on monday using a gas tester at an MOT station nearby.
I am going to order a Collins -31 actuator this weekend.

Car has new rebuild engine on original spec. New original turbocharger. AIRTEC intercooler, stainless mongoose exhaust, K&N panel filter. Otherwise stock.
Only thing I need to mention is the extra temp sensor which is mounted on the waterhose next to the auxillary air valve, is not mounted. Connector is present, but the pipe fr the sensor is missing. I have seen this on more RS Turbo's, but I don't know which ECU needs them or not.

So what do you guys think. Should it be fine with CO adjusted and new actuator, or is there something wrong with the car?

Thank you!!

Versus_Creations

iTrader: (1)

Being in Netherlands ypu will need to tune it yourself. Have a read of the setup guide I wrote which will help you set the basics and at least be able to get more help once you follow what to do.

Piston Broke

You have done the best basic checks, try removing and having the injectors tested they might not be doing as needed spray pattern wise etc at the different pressures. Testing here is only around Ł5 a injector and a cheap place to start

Dr. Ickxs

I've used your setup guide, and all was ok.
I have mounted the extra coolant temp sensor, and a Forge actuator with green spring. Power wise a big step forward, but still a flat spot between 3100 and 3800 rpm.
Going to exchange the anti knock sensor with a spare.

Dr. Ickxs

I will check those.
I got 2 sets of spare injectors. Used, but ultrasonic cleaned. Just like the ones in the car (500miles ago).

Dr. Ickxs

Ok. New update. Fuel pump became noisy, so placed new uprated one.
One injector had bad spray pattern, so place 4 brand new original Bosch ones.
Replace sparkplugs with iridium ones. The old plug of cyl. 1 looked like running lean.
Placed a lambda sensor in the exhaust and with an AFR meter, it shows rich on full throttle. So that should be OK.
Powerwise all is fine now, but still starting on 2 or 3 cylinders when cold. Disconnected cold start injector, but still starting on 2/3 cyl. Takes longer to start then, as expected. Also still holds back at half throttle on 3200 to 4000rpm. Full throttle is fine.
I found out that the remaining fuel pressure after the pump is still there after 2 weeks, but when I exchanged tje injectors, there was none remaining fuel pressure on any of the 4.
Broken regulator or distrubuter?